dragon,devtty: mask chars for braindead video
Makefile: allow for banking tests

No I've no idea how I'd do the banking functions either yet, but it proves
we can build most of it (still busted for device I/O calls)
Merge branch 'master' of https://github.com/EtchedPixels/FUZIX
binman: Clean crap out of tools binman version
start: fix screw up in tty changes
z80pack: Make the bootblock in the Makefile

Update README
z80pack, tricks: update bankfork

We now use all but 4K for base memory so we may need to copy more space.
Without this fix programs with large or no chmem crashes in fork()
usermem: fix error handling
usermem-z80: return 0
z80pack: put the kernel flag in common

As this is checked with the kernel not mapped it's important it lives somewhere
more suitable
process: kernel flag has moved to common
binman: memcpy the initialized data over

This accidentally got removed when I stripped it down from the full
featured kernel version.
6502test: flesh out a little of the 6502 init paths
execve: remove some debug noise
6502: Start fleshing out how the port would work

Very incomplete at this point
lowlevel-z80: di/ei handling

Handle both di/ei restore cases don't assume we are just stacking disables
dragon: continue fleshing out

At this point it's a fairly complete build minus I/O devices but with some
guesswork on how we will deal with irq and syscall handling given the odd
memory mappings.

It does at least suggest that we can put it in cartridge + single task in
memory mode.